基于核磁共振的致密岩心流体赋存状态及动用性评价

Occurrence State and Availability Evaluation of Fluid in Tight Cores Based on Nuclear Magnetic Resonance

致密储层地质条件差、渗透率低、束缚流体饱和度高,只有可流动流体部分才具有开采价值,研究储层岩石流体赋存状态及动用性具有重要意义。本文利用核磁共振岩心分析技术所能提供的T2分布及T2截止值,计算可动流体百分数和可动流体孔隙度,从而确定致密岩心的微观孔隙结构及其流体的可动用性。对油田现场18块不同岩心进行了实验测试,结果表明,该方法能够有效确定致密砂岩储层的微观孔隙结构及可动流体赋存特征,为科学合理的开发超低渗油藏提供了理论依据。

Tight reservoir has poor geological conditions,low permeability and high irreducible fluid saturation,and only the part of flowing fluid has mining value.It is of great significance to study the occurrence and availability of fluid in reservoir rock.Based on the T2 distribution and T2 cut-off value provided by nuclear magnetic resonance core analysis technology,this paper calculates the movable fluid percentage and movable fluid porosity,so as to determine the micro pore structure of tight core and the mobility of fluid.The experimental results of 18 different cores show that this method can effectively determine the micro pore structure and movable fluid occurrence characteristics of tight sandstone reservoir,which provides a theoretical basis for scientific and reasonable development of ultra-low permeability reservoir.